Internal combustion engine



Dec. 12, 1933. F. WEINBERG INTERNAL COMBUSTION ENGINE Filed June 7, 1928 INVENTOR M ATTOR N EY5.

Patented Dec. 12, 1933 PATENT OFFICE INTERNAL COMBUSTION ENGINE Frederick Weinberg, Detroit, Mich. ApplicationJune 7,1928. Serial No. 283,566

16 Claims.

My invention relates to improvements in internal combustion engines and their method of operation and is adaptable to either the conven tional two or four cycle type.

The object is to increase the efficiency of such an engine, and particularly when used in automobile practice, and includes as a means to such end a substantial increase in fuel compression,

a more nearly uniform fuel compression at the time of firing notwithstanding widely different running conditions and wide variations in the quantity of fuel admitted, and a more thoroughly complete and homogeneous fuel mixture.

The idea of increasing the efficiency of the engine through increasing the ratio of compres- 'sion is not new. An increase in compression re-' sults in a more thoroughly complete and homogeneous mixture as it reduces the free paths of the fuel and air molecules and increases the frequency of their collision and therebyfacilitates combustion. It is especially desirable in automobile practice for while wide open throttle running is quite common in marine and aeronautical work, it is the exception with the automobile, and at partly open throttle positions the efliciency'is comparatively low and the specific 7 fuel consumption is high.

The upper limit of compression is determined 'by the point at which knock results, and doped bustion chamber notwithstanding that such a practice results in the expansion of the fuel which reduces the volumetric efficiency.

I propose to accomplish all these objects, attaining a substantially high ratio of compression and maintaining a more nearly uniform compression, by first compressing fuel to a point substantially higher than now practiced in an engine of the type described with such point approaching yet being safely below the autoignition point, depending upon thecharacter of fuel used, and secondly, to follow such high compression period with an expansion period which immediately precedes the firing and to control such expansion period to approach uniformity of compression at the time of firing.

At wide open throttle positions the density or quantity of fuel taken into the combustion ways to make it a function of the previous comchamber is substantially greater than at partly open throttle positions and the resulting compression, with the conventional engine which compresses to a uniform volume, is consequently substantially greater and my limit of compres- '69 sion is therefore predetermined to come below while approaching the autoignition point of the relatively high density charges. The expansion period which I propose to introduce into the conventional cycle of operation is consequently greater at such times than'at intermediate or partly open throttle positions. Due to the substantially greater compression obtained in my method of operation, I produce a great turbulence in the fuel mixture and a very thorough interminglingof the fuel and air molecules, and the mixture is heated to a substantial degree solely by the compression exerted thereon which permits me to take fuel into the combustion chamber at a relatively low temperature and not 5 rarefied as is the case with preheated fuel. Furthermore, I can employ heavier and lower grade fuels.

The expansion period which I introduce into the conventional cycle varies in extent an amount which is a function of the previously high compression so as to approach a substantially uniform and constant compression at the time for firing.

Even though the ultimate compression at such time is not constant, it approaches much closer to that point than with the present practice and my improvement results in a substantial minimizing of the wide variations which now exist.

This expansion period isregulated in various 1-90 pression and a preferred method and means is to advance or retard the timer, which regulates the firing point, automaticall with the control exercised over the throttle, retarding the timer as the throttle opening increases and advancing it as the throttle opening decreases. Other meanssuch as basing this control upon the depression in the intake manifold or the pressure of the exhaust gases may be employed.

A further advantage resulting from my improved method of and means lies in the fact that due to a substantial retardation of combustion, the crank, in a reciprocating engine of the type described, is in an exceedingly favorable position to receive power impulses and avoid detonation.

In the drawing,

Fig. 1 is a broken away elevation, partly in diagram, of my invention.

Fig. 2 is an elevation partly in diagram of my invention. I

Figs. 3, 4, 5 and 6, are fragmentary views of separate modifications partly in elevation and partly in diagram.

Fig. 7 shows my invention mounted in elevation on an automobile.

Fig. 8 is an elevation of a two cycle engine em-. bodying my invention.

In the drawing, let 38 indicate one of the combustion chambers or cylindersof an internal combustion engine, 37 a working piston, 39 a crank connected therewith to receive the power impulse therefrom, 31 the intake manifold through which the fuel mixture is supplied to the combustion chamber. and 13 the throttle valve controlling the admission of the fuel. i

This throttle valve is mounted upon a spindle 36 upon the outer end of which is carried a cam 16, having an extended arm '32 held by a spring" 15 to normally close the throttle valve which is opened by the manually operable accelerators 21 and 22 against the resistance of the spring 15. 1

i The major feature of my invention resides, however, in the novel method of operating the internal combustion engine and the novel means therefor provided. In the operation of the ordinary internal combustion engine, either of the four cycle or two cycle type, fuel mixture is drawn into the combustion chamber in a .varying quantity or at varying densities depending upon various factors, the principal one of which is the control exercised over the engine bythe'throttle. At wide open throttle position the densityis high and the efficiency is correspondingly higher than at the partially open throttle positions where the density is .relatively low and the resulting compression by the piston is-as a consequence substantially vIn Fig. 1'the'throttle'l3 is shown at apartially open position and in Fig.2 it is shown fully open as it is also in Fig. '7. I provide mechanism operable to advance or retard'the firing depending upon thecompression of the fuel mixture obtained in the combustion chamber and which includes the introduction of a fuelexpansion period into the cycle of operation immediately following the compression period and preceding'the firing and which likewise includes the compression of the fuel. mixture during the compression period to a substantially higher degree than has heretofore been the practice and to a degree limited by the autoignition point of the fuel mixture used.

In Figs. 21and 7, ,I show mechanical linkage coupling the throttle with the timer l8 and it is hereillustrated as an arm 17 held by spring 26 against the cam 16 to advance the timer as the throttleis movedtoward the closed position and then allowed to expand, due-to the retardation of the timer, through a new period- This expansion period varies as has been set forth with the positionof the throttle which controls. the quantity or density of the fuel mixture admitted to the combustion chamber so that-the expansion period varieswith the density or quantity of fuel mixture admitted into the combustion chamber thereby thewideva-riations in compression at the time of firing are minimized and. a more .or less constant compression is attained which compression is substantially higher than .that now the rule.

In Fig. 3 the same result is obtained through linking the timer mechanically with a diaphragm 33 responsive to the depression in the intake manifold and thereby to the speed and power output of the engine.

In Fig. 4 a second modification appears where a piston 34 is responsive to the depression in the intake manifold to control the position of the timer 18. A compression spring produces the counter movement which in Fig. 3 is produced by the resiliency of the membrane itself. These modifications shown in Figs. 3 and 4 have yielded the best practical results.

I V In Fig. 5 connected linkage couples the throttle with the timer 18.

In Fig, 6 the piston 35 is responsive to the pressure of, the exhaust gas passing through the exhaust 25 to control the position of the timer which exhaust gas pressure varies with the quantity or density of m'xture admitted into the combustion chamber. A tension spring produces the counter movement in this construction.

' InFig. 8 a two cycle engine is shown having a piston. 37 and otherwise similariy numbered parts, the only difference being the-application of the device to a two cycle engineas compared with a iourv cycle engine. I c

In the operation of an internal combustion engine embodying my invention the, maximum compression is determined so asto be as high as possible yet safely below the autoignition point of the fuel mixture employed at wide open throttle position and the compression at partially open throttle positions would be less and the expansion stroke which I interpose would vary as a function of this compression so as to'appreach a substantially constant compression :at the time of firing. Due to the fact that fuelis taken in without preheating, the heat of the mixture results from the compression thereof by It is possible to use the engine with the .throttle substantially closed and, for example, while idling substantially in the fashion in which a similar engine is used at the present time but due to the high compression attained a great load is placed upon the starting mechanism and when starting it is desirable to close down the throttle or the choke 23 and turn the engine over for a period necessary to build up suflicient momentum to carry it on as against the substantially-higher compression developed when the throttle is'-.

opened. I I a converted into the type of engine here described.

The firing may take place at any point between the dead center at closed throttle position and a position approximately 35 degrees therefrom, depending greatly upon the firing lag of the-fuel.

What I claim is:

1. That method of operating aninternal combust-ion compression engine receiving fuel mixture charges of varying densitiescomprising maintaining a substantially uniform density of the fuel mixture at thetime of firing by interposing. in f its the cycle an expansion period following the compression period and preceding the firing and varying the extent of such expansion period directly as the density of the received fuel mixture charges varies.

2. That method of operating an internal combustion compression engine receiving fuel mixture in charges of varying densities comprising providing in its cycle of operation a fuel mixture expansion period immediately preceding the firing and increasing the extent of said expansion period as the fuel mixture charges increase in density.

3. That method of operating an internal combustion compression engine receiving fuel mixture increments that vary in density comprising introducing a variable fuel mixture expansion period into the cycle immediately preceding the firing and regulating said period to minimize the variations in compression at the time of firing.

4. That method of operating an internal combustion compression engine receiving fuelmixture charges of varying densities comprising compressing the increments of relatively high initial density to a point substantially higher than the point of their compression at the time of firing, introducing an expansion period into the cycle of operation immediately following such compression prior to the firing during which said compressed charges expand; compressing charges of relatively lower initial density to a point higher than the point of their compression at the time of firing and allowing them to expand prior to the firing to maintain a substantially high and relatively uniform compression at the time of firing.

5. That method of operating an internal combustion compression engine receiving fuel increments that vary in density comprising compressing each charge to substantially the same volume and thereafter and prior to firing allowing the charges of relatively high compression to expand a substantially greater amount than the increments of relatively low compression.

6. That method of operating an internal combustion compression engine receiving fuel mixture increments that vary in density comprising compressing the increments of maximum density to a point approaching yet safely below the point of autoignition and then allowing said increments to expand prior to firing for a substantial amount which varies as a function of their maximum compression.

7. That method of operating an internal combustion engine of a conventional four cycle type comprising interposing a variable fuel mixture expansion period in its cycle immediately following the fuel mixture compression period and immediately preceding the firing to maintain a substantially high and approximately uniform compression.

8. That method of operating an internal combustion engine of the two cycle type comprising interposing a variable fuel mixture expansion period in its cycle immediately following the fuel mixture compression period and immediately preceding the firing to maintain a substantially high and approximately uniform compression.

. 9. In an internal combustion engine, means producing a relatively high variable initial compression, ignition mechanism, and means pro viding a preliminary expansion period and automatically governing said ignition mechanism to control the expansion period as a function of said 7 form and constant compression at the firing point.

10. An internal combustion engine comprising in combination, a combustion chamber, means for introducing therein a relatively cool and homogeneous fuel mixture, means creating a relatively high compression of said fuel within the chamber, means for providing an expansion period prior to firing, and means whereby the expansion period prior to firing is automatically varied to provide substantially uniform compression at the time of firing.

11. The process of operating an internal combustion engine, consisting in regulating the parts to compress with full open throttle to a higher pressure than that at which it is desired to ignite the charge, allowing said charge to expand to the desired pressure and igniting the charge at the last named pressure and varying the point of ignition to correspond to degrees of such expansion that will secure the same degree of compression at the time of ignition for all degrees 0 throttling at the given speed.

12. An internal combustion engine provided with fuel compression mechanism operable to produce a relatively high variable initial compression of the fuel mixture followed by an expansion period, ignition'mechanism to fire the fuel mixture, and means operable to automatically control said expansion period as a function of the initial compression of the fuel mixture to obtain a substantially uniform constant compression of the fuel mixture upon firing.

13. That method of operating an internal combustion compression engine receiving fuel mixture increments that vary in density comprising introducing a variable fuel mixture expansion .period into the cycle immediately preceding the firing and regulating said period in response to variations in exhaust pressure of the engine to minimize the variations in compresson at the time of firing.

14. An internal combustion engine provided with fuel compression mechanism operable to produce a relatively high variable initial compression 'of the fuel mixture followed by an expansion period, ignition mechanism to fire the fuel mixture, and means controlled by the exhaust pressure of the engine operable to automatically control said expansion period as a function of the initial compression of the fuel mixture to obtain a substantially uniform constant compression of the fuel mixture upon firing.

15. An internal combustion engine provided with fuel compression mechanism operable to produce a relatively high variable initial compression of the fuel mixture followed by an expansion period, throttle mechanism, ignition mechanism to fire the fuel mixture, and means controlled by the throttle mechanism operable to automatically control said expansion period as a function of the initial compression of the fuel mixture to obtain a substantially uniform constant compression of the fuel mixture upon firing.

16. An internal combustion engine provided with fuel compression mechanism operable to produce a relatively high variable initial compression of the fuel mixture followed by an expansion period, ignition mechanism to fire the fuel mixture, and means controlled by the depression in the intake manifold operable to automatically control said expansion period as a function of the initial compression of the fuel mixture to obtain a substantially uniform constant compression of the fuel mixture upon firing.

FREDERICK WEINBERG. 

